Conventionally, refrigeration apparatuses which perform refrigeration cycles have been known in the prior art. Such a type of refrigeration apparatus has been used widely as an air conditioning apparatus for providing indoor space heating/cooling and as a cooler for a refrigerator or other like apparatus for keeping food, etc., cool. There is a refrigeration apparatus which is configured such that it provides both air conditioning and cold/freeze storing (see, for example, JP Patent Application Publication (Kokai) No. 2001-280749).
Generally, in such a type of refrigeration apparatus, a plurality of utilization-side heat exchangers (heat exchangers for cold storage, freeze storage, and air conditioning) disposed in utilization-side units (such as showcases for cold storage and freeze storage, indoor units for air conditioning etc.) are connected in parallel to a heat source-side heat exchanger (operating as an outdoor heat exchanger) of a heat source-side unit (operating as an outdoor unit) installed outdoors, by their respective liquid-side communication lines and gas-side communication lines. When installed in, for example, a convenience store, such a type of refrigeration apparatus is alone able to provide both indoor space air conditioning and showcase refrigeration.
In the conventional refrigeration apparatus, a refrigerant circuit thereof is formed into a circuit having two different piping systems, namely a cold/freeze storage piping system and an air conditioning piping system. Consequently, two communication lines are used for each of the liquid and gas lines, therefore resulting in an increase in the number of communication lines. This complicates the work of pipe connection, and there is the possibility that piping will be done improperly.
With a view to coping with the problems described above, the applicant of the present application devised a refrigeration apparatus in which it is arranged that a single liquid-side communication line is shared between liquid lines of two piping systems, and that the liquid-side communication line is positioned in side-by-side and contacting relationship with a low pressure gas-side communication line of a cold/freeze storage piping system, and the applicant of the present application already filed a patent application for this refrigeration apparatus (see JP Patent Application Publication (Kokai) No. 2004-044921). In this refrigeration apparatus, the number of communication lines is reduced, thereby reducing the possibility that pipes will be connected improperly. Besides, heat exchange takes place between liquid refrigerant in the liquid-side communication line and gas refrigerant in the low pressure gas-side communication line of the cold/freeze storage piping system. The liquid refrigerant is supercooled by the suction-side gas refrigerant, and the capability to provide refrigeration is improved.
The conventional refrigeration apparatus has a refrigerant circuit with a configuration as specifically shown in FIG. 27. FIG. 27 shows an outdoor unit (101), an indoor unit (102), a cold storage showcase (103) which is a cold storage unit, and a freeze storage showcase (104) which is a freeze storage unit. The outdoor unit (101) is provided with compression mechanisms (105,106), an outdoor heat exchanger (107), an outdoor expansion valve (108), and a receiver (109). The indoor unit (102) is provided with an indoor heat exchanger (110) and an indoor expansion valve (111). Additionally, the cold storage showcase (103) is provided with a cold storage heat exchanger (112) and a cold storage expansion valve (113). The freeze storage showcase (104) is provided with a freeze storage heat exchanger (114), a freeze storage expansion valve (115), and a booster compressor (116).
This refrigeration apparatus has a refrigerant circuit (120) which is provided with a cold/freeze storage piping system-side circuit and an air conditioning piping system-side circuit. The cold/freeze storage piping system-side circuit is configured so that refrigerant circulates between the outdoor heat exchanger (107) and the cold storage and freeze storage heat exchangers (112,114). The air conditioning piping system-side circuit is configured so that refrigerant circulates reversibly between the outdoor heat exchanger (107) and the indoor heat exchanger (110). And, a single liquid-side communication line (121) is shared between liquid lines of each piping system and, in addition, the liquid-side communication line (121) is positioned in side-by-side relationship with a low pressure gas-side communication line (122) of the cold/freeze storage piping system.